package com.heima.schedule.service.impl;

import com.alibaba.fastjson.JSON;
import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import com.heima.common.redis.RedisCacheService;
import com.heima.model.common.constants.ScheduleConstants;
import com.heima.model.schedule.dtos.Task;
import com.heima.model.schedule.pojos.Taskinfo;
import com.heima.model.schedule.pojos.TaskinfoLogs;
import com.heima.schedule.mapper.TaskinfoLogsMapper;
import com.heima.schedule.mapper.TaskinfoMapper;
import com.heima.schedule.service.TaskService;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Service;

import javax.annotation.PostConstruct;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
import java.util.Set;

@Service
@Slf4j
public class TaskServiceImpl implements TaskService {

    @Autowired
    private TaskinfoMapper taskinfoMapper;

    @Autowired
    private TaskinfoLogsMapper taskinfoLogsMapper;

    @Autowired
    private RedisCacheService cacheService;

    /**
     * 添加延时任务
     * @param task
     * @return
     */
    @Override
    public long addTask(Task task) {
//        1.添加任务到数据库中
        boolean success = addTaskToDb(task);
        if (success) {
//        2.添加任务到redis
            addTaskToRedis(task);
        }
        return task.getTaskId();
    }

    /**
     * 取消任务
     * @param taskId        任务id
     * @return
     */
    @Override
    public boolean deleteTask(long taskId) {
        boolean flag = false;
        //1.删除数据库中的任务
        int success = taskinfoMapper.deleteById(taskId);
        if(success==0){
            return flag;
        }
        try {
            //2.更新日志状态
            TaskinfoLogs taskinfoLogs = taskinfoLogsMapper.selectById(taskId);
            taskinfoLogs.setStatus(ScheduleConstants.CANCELLED);
            taskinfoLogsMapper.updateById(taskinfoLogs);
            //3.删除redis中的任务
            Task task = new Task();
            BeanUtils.copyProperties(taskinfoLogs,task);
            task.setExecuteTime(taskinfoLogs.getExecuteTime().getTime());
            String key = task.getTaskType()+"_"+task.getPriority();
            if(task.getExecuteTime()<=System.currentTimeMillis()) {
                cacheService.lRemove(ScheduleConstants.TOPIC + key, 0, JSON.toJSONString(task));
            }else{
                cacheService.zRemove(ScheduleConstants.FUTURE + key, JSON.toJSONString(task));
            }
            flag = true;
        } catch (Exception e) {
            log.error("删除任务失败",e);
            e.printStackTrace();
        }
        return flag;
    }

    /**
     * 按照类型和优先级来拉取任务
     * @param type
     * @param priority
     * @return
     */
    @Override
    public Task poll(int type, int priority) {
        Task task = null;

        try {
            String key = type + "_" + priority;
//        从redis中拉取数据 pop
            String taskJson = cacheService.lRightPop(ScheduleConstants.TOPIC + key);
            if (StringUtils.isNotBlank(taskJson)) {
                task = JSON.parseObject(taskJson, Task.class);

//            修改数据库信息
                updateDb(task.getTaskId(), ScheduleConstants.EXECUTED);
            }
        } catch (Exception e) {
            e.printStackTrace();
            log.error("poll task exception");
        }
        return task;
    }

    /**
     * 定时刷新队列，每分钟刷新
     */
    @Override
    @Scheduled(cron = "0 */1 * * * ?")
    public void refresh() {
        log.info(System.currentTimeMillis() / 1000 + "执行了定时任务");
        String token = cacheService.tryLock("FUTURE_TASK_SYNC", 1000 * 30);
        if (StringUtils.isNotBlank(token)) {
            log.info("未来数据定时刷新---定时任务");
            // 获取所有未来数据集合的key值
            Set<String> futureKeys = cacheService.scan(ScheduleConstants.FUTURE + "*");// future_*
            for (String futureKey : futureKeys) { // future_250_250

                String topicKey = ScheduleConstants.TOPIC + futureKey.split(ScheduleConstants.FUTURE)[1];
                //获取该组key下当前需要消费的任务数据
                Set<String> tasks = cacheService.zRangeByScore(futureKey, 0, System.currentTimeMillis());
                if (!tasks.isEmpty()) {
                    //将这些任务数据添加到消费者队列中
                    cacheService.refreshWithPipeline(futureKey, topicKey, tasks);
                    log.info("成功的将" + futureKey + "下的当前需要执行的任务数据刷新到" + topicKey + "下");
                }
            }
        }
    }

    /**
     * 数据库任务定时同步到redis
     */
    @Override
    @Scheduled(cron = "0 */5 * * * ?")
    @PostConstruct
    public void reloadData() {
//        清理缓存中的数据 list zset
        clearCache();


//        查询符合条件的任务 小于未来5分钟的数据
        log.info("数据库数据同步到缓存");
        Calendar calendar = Calendar.getInstance();
        calendar.add(Calendar.MINUTE, 5);
        // 查看小于未来5分钟的所有任务
        List<Taskinfo> taskinfos = taskinfoMapper.selectList(Wrappers.<Taskinfo>lambdaQuery().lt(Taskinfo::getExecuteTime, calendar.getTime()));

//        把任务添加到redis
        if (taskinfos != null && taskinfos.size() > 0) {
            for (Taskinfo taskinfo : taskinfos) {
                Task task = new Task();
                BeanUtils.copyProperties(taskinfo, task);
                task.setExecuteTime(taskinfo.getExecuteTime().getTime());
                addTaskToRedis(task);
            }
        }

        log.info("数据库的任务同步到了redis");
    }

    /**
     * 清理缓存中的数据 list zset
     */
    public void clearCache() {
        // 删除缓存中未来数据集合和当前消费者队列的所有key
        Set<String> topicKeys = cacheService.scan(ScheduleConstants.TOPIC + "*");
        Set<String> futureKeys = cacheService.scan(ScheduleConstants.FUTURE + "*");
        cacheService.delete(topicKeys);
        cacheService.delete(futureKeys);
    }

    /**
     * 删除redis中的数据
     * @param task
     */
    private void removeTaskFromCache(Task task) {
        String key = task.getTaskType() + "_" + task.getPriority();
        if (task.getExecuteTime() <= System.currentTimeMillis()) {
            cacheService.lRemove(ScheduleConstants.TOPIC + key, 0, JSON.toJSONString(task));
        } else {
            cacheService.zRemove(ScheduleConstants.FUTURE + key, JSON.toJSONString(task));
        }
    }

    /**
     * 删除任务，更新任务日志
     * @param taskId
     * @param status
     * @return
     */
    private Task updateDb(long taskId, int status) {
        Task task = null;
        try {
//        删除任务
            taskinfoMapper.deleteById(taskId);

//        更新任务日志
            TaskinfoLogs taskinfoLogs = taskinfoLogsMapper.selectById(taskId);
            taskinfoLogs.setStatus(status);
            taskinfoLogsMapper.updateById(taskinfoLogs);

            task = new Task();
            BeanUtils.copyProperties(taskinfoLogs, task);
            task.setExecuteTime(taskinfoLogs.getExecuteTime().getTime());
        } catch (Exception e) {
            log.error("task cancel exception taskId={}", taskId);
        }
        return task;
    }

    /**
     * 把任务添加到redis中
     * @param task
     */
    private void addTaskToRedis(Task task) {
        String key = task.getTaskType() + "_" + task.getPriority();

//        获取5分钟之后的时间 毫秒值
        Calendar calendar = Calendar.getInstance();
        calendar.add(Calendar.MINUTE, 5);
        long nextScheduleTime = calendar.getTimeInMillis();

//        2.1如果任务的执行时间小于等于当前时间，存入list
        if (task.getExecuteTime() <= System.currentTimeMillis()) {
            cacheService.lLeftPush(ScheduleConstants.TOPIC + key, JSON.toJSONString(task));
        } else if (task.getExecuteTime() <= nextScheduleTime) {
//        2.2如果任务的执行时间大于当前时间 && 小于等于预设时间（未来5分钟）存入zset中
            cacheService.zAdd(ScheduleConstants.FUTURE + key, JSON.toJSONString(task), task.getExecuteTime());
        }
    }

    /**
     * 添加任务到数据库中
     * @param task
     * @return
     */
    private boolean addTaskToDb(Task task) {
        boolean flag = true;

        try {
//        保存任务表
            Taskinfo taskinfo = new Taskinfo();
            BeanUtils.copyProperties(task, taskinfo);
            taskinfo.setExecuteTime(new Date(task.getExecuteTime()));
            taskinfoMapper.insert(taskinfo);

            task.setTaskId(taskinfo.getTaskId());

//        保存任务日志数据
            TaskinfoLogs taskinfoLogs = new TaskinfoLogs();
            BeanUtils.copyProperties(taskinfo, taskinfoLogs);
            taskinfoLogs.setVersion(1);
            taskinfoLogs.setStatus(0);
            taskinfoLogsMapper.insert(taskinfoLogs);
        } catch (Exception e) {
            e.printStackTrace();
            flag = false;
        }

        return flag;
    }
}
